Venomous Spiders Never Before Documented In CT Found In Apartment Building

WALLINGFORD, CT — For years, spiders lurking in the basement of a Wallingford apartment building were nothing more than an occasional nuisance. Finding a few eight-legged neighbors in a New England basement is hardly unusual.

But these weren't ordinary basement spiders — they belonged to a venomous species native to the Mediterranean region that had never been documented in Connecticut.

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When a pest management professional collected several specimens from the building in December 2025, he was stumped. He brought the spiders to a state entomologist, who enlisted a national expert to help confirm their identity: Mediterranean recluse spiders.

Dr. Gale E. Ridge, an associate scientist and entomologist at the Connecticut Agricultural Experiment Station, recognized the specimens as recluse spiders but wasn't certain which species she was looking at.

She sent a photograph of a male spider's reproductive structure to Richard Vetter, a nationally recognized expert on recluse spiders.

"He was back in touch with me in 15 minutes," Ridge said.

The confirmation marked the first documented occurrence of Mediterranean recluse spiders in Connecticut. But the spiders themselves may have been living in the building for much longer, as residents had seen them for years.

How Did Mediterranean Recluse Spiders Get To Connecticut?

Native to southern Europe and northern Africa, Mediterranean recluse spiders are naturally cave-dwelling creatures that prefer dark, secluded environments.

In colder climates, that makes basements, crawl spaces and underground utility tunnels particularly attractive habitats.

The spiders cannot survive outdoors through Connecticut winters, Ridge said, but they can establish themselves inside buildings where temperatures remain relatively stable.

Exactly how the spiders arrived in Wallingford remains unknown. Ridge suspects they may have been transported into the building with furniture or other belongings.

While uncommon, Mediterranean recluse spiders have been documented in 22 states, including in buildings along the East Coast.

Researchers studying federal buildings in Washington, D.C., discovered that the spiders could establish substantial populations in underground spaces without attracting much attention from the people working above them.

"Washington D.C. actually has a lot of them in the government areas," Ridge remarked. "There's so much moving of staff in the state department, in and out of the country with furniture and personal effects, they're brought in that way."

Should Connecticut Residents Be Worried?

Ridge said that while the discovery was unusual, residents shouldn't be alarmed.

"These spiders generally run from you. They stay very much to themselves," Ridge said, explaining that the nocturnal spiders are shy and typically hide in cracks and crevices, away from people.

Like other recluse spiders, however, Mediterranean recluses possess venom that can cause tissue damage in humans. Serious reactions are possible, although encounters and bites are uncommon.

The spiders generally bite defensively, like when accidentally trapped against someone's skin, rather than actively pursuing people.

Spiders might be scary, but they also play an important role in controlling insect populations. Mediterranean recluses feed on insects including cockroaches and termites, according to Ridge.

"If it wasn't for the activity of spiders and their hunting, we would be about six feet deep in flies worldwide," Ridge said. She generally recommends leaving spiders undisturbed.

The Wallingford discovery may not be the last of its kind. Ridge said she wouldn't be surprised if Mediterranean recluse spiders eventually turned up in other Connecticut buildings.

"It's just a matter of having the right person in the right place," she said.

Anyone who encounters an unfamiliar spider can contact the Connecticut Agricultural Experiment Station for help identifying it. Ridge recommends submitting clear photographs, particularly images showing the spider's eyes, along with information about where it was found.